Which One?

[Joshwainwright]

What type of filter should I use for this tank?

I'm going to be having a Betta in it...

 

[drobbyb]

You have many options. You could use anything from a sponge type filter, box filter, or a hang on back type power filter.

 

[Essjay31 146]

For a betta, you'll need a filter with a gentle flow. What's the capacity of the tank? My betta is in a 25litre tank and I have an elite mini internal filter. The amount and dierction of flow are both adjustable. And the size is fine for 1 betta and a snail.

 

[Joshwainwright]

I've no idea of the size as of the shape...

 

[OldMan47]

Looks like probably less than 5 gallons capacity. In a tank that small I would probably use a small air driven box filter or a small air driven sponge filter. That would of course mean that you would need an air pump to run it.

 

[saz326]

Would I be mad saying undergravel filter?

I know they're not up to coping with much bioload, but a Betta and a snail wouldnt make that much mess.

I mean, by the time you've stuck a filter in there you loose space for the fish to swim. At least and undergravel jobby is hidden and wont look ugly.